(1) Field of Invention
The present invention relates to wireless mobile telephone systems incorporating telephone instruments that are capable of being simple in form, e.g. keyless and battery-less, relatively inexpensive and conveniently available for flexible use, both for conversational and DTMF communication.
(2) Background Description
In recent years, wireless mobile telephones have come into extensive and widespread use supported by various forms of central equipment. Generally, wireless telephone instruments, sometimes called "mobile stations" (MS) may be accommodated for example by geographically defined cells. Such systems afford the capability for wireless telephone instruments to communicate with other telephone terminals through the public telephone network while physically roving between locations.
Typically, in mobile wireless systems, individual wireless telephone instruments communicate at an initial level with central equipment, sometimes called "base stations" (BS). Operating with other components in a composite system, the geographically-spaced base stations enable mobile telephone instruments to roam through various geographic areas or cells. Thus, from various locations a mobile telephone instrument can communicate with virtually any telephone terminal throughout the entire dial-up telephone network, sometimes called the "public switched telephone network" (PSTN). Systems may also include a unit called a "mobile switching center" (MSC) for accommodating communication through the PSTN. Accordingly, through wireless mobile telephone communication can be quite effective, a need continues to exist for further convenience and flexibility in the use of mobile telephone instruments.
In the interests of simplicity and economy, it has been proposed to provide voice activated wireless telephone systems using instruments without a numerical keypad, that is, keyless instruments. Essentially, voice-dialing for such instruments is accommodated by voice recognition of spoken numerals to accomplish DTMF signals (dual tone multi frequency) for continual dialing operations. For example, see a co-pending U.S. patent application entitled: WIRELESS PREPAID TELEPHONE SYSTEM FOR PROGRAMMED AND EXPANDED USE, Ser. No. 09/226,178, filed Jan. 4, 1999 which is a continuation in part of an application entitled WIRELESS PREPAID TELEPHONE SYSTEM WITH EXTENDED CAPABILITY, Ser. No. 08/955,338, filed Oct. 21, 1997, which is a continuation in part of an application entitled WIRELESS PREPAID TELEPHONE SYSTEM WITH DISPENSABLE INSTRUMENTS, Ser. No. 08/878,864, filed Jun. 19, 1997, all incorporated by reference herein. Such systems convert audio signals from a telephone instrument that are representative of spoken numerals to DTMF signals for dial up connection to another terminal for vocal communication. However greater flexibility may be desirable in that regard.
In another regard, a weak link in mobile telephone communications involves power for the telephone instrument, e.g., the battery. Essentially, the user of a mobile telephone instrument must always be concerned with the state of the instrument's battery. If an instrument is not used for a time, concern grows for the charge state of the battery. Furthermore, for some batteries, certain charging patterns may be detrimental to the battery power cycle. For example, to maintain an effective power cycle of a battery, it may be important to fully discharge the battery before recharging. Accordingly, maintaining a mobile telephone battery charged for operation sometimes is inconvenient. Essentially without careful planning, a mobile instrument user may be faced with a discharged battery when the need for the instrument is most urgent.
As a related consideration, it is noteworthy that the power pack or battery of a mobile telephone instrument typically accounts for a considerable portion of the instrument's weight, cost and volume. Thus, the battery of a mobile telephone instrument not only presents a limitation on the use of such instruments but also imposes constraints on the design of such instruments.
In view of the above considerations, it may be appreciated that a need exists for mobile telephone instruments which avoid the use of a battery. Additionally, as indicated, a need exists for greater convenience and flexibility with regard to keyless mobile instruments, specifically confirming digital communication and affording communication at any time by either conversational speech (voice) or by DTMF signals (digital). That is, a need exists for a system incorporating mobile instruments that are capable of using voice selectively to communicate either conversationally by speech or digitally by DTMF tones (0-9 etc.).